Automotive driving instruction system

ABSTRACT

An automotive driving instruction system which comprises a plurality of sensors including a vehicle speed sensor etc. mounted at various parts of the automobile, a computer for reading the outputs of the sensors for calculating the driving conditions of the automobile, and a replaceable external memory unit. The computer calculates a plurality of values representing the driving conditions of the automobile on the basis of the outputs of the sensors, and controls to generate an alarm when any of the values thus calculated becomes to corresponding one of a plurality of predetermined values. Also, the accumulated value of the alarms and the respective accumulated values of the alarms for each of causes of alarming are stored in the external memory unit. At the end of a driving, the external memory unit is demounted, so that any habits of the driver is determined from the data stored in the external memory unit to contribute to the correction thereof.

BACKGROUND OF THE INVENTION

The present invention relates to a driving instruction system intendedto contribute to the driving safety and the saving of energy bymonitoring the driving conditions all the time and issuing an alarmagainst an unsafe behaviour or an uneconomical driving operation of thedriver.

Conventionally it is known a system in which the automobile speed,engine rotational speed or abrupt braking is detected and an alarm isissued against any abnormal value of such an operation.

Generally, on the other hand, an operating recorder is mounted in anautomobile and the figures recorded in this device are analyzed therebyto determine the driving conditions.

The true driving conditions cannot be determined by a single phenomenonsuch as the vehicle speed or engine rotational speed, and it has so farbeen difficult to issue a proper alarm satisfactory to the driver.

Further, in conventional systems, an alarm is simply issued upondetection of an improper driving condition, and what has been improperis not analyzed nor used as data for educational control of the driver.

Also, in spite of the fact that the changes in vehicle speed, enginerotational speed or operating conditions are recorded in the operatingrecorder and the record is analyzed, the resolution of the recordingpaper of the operating recorder is limited so that a bulky and expensivemachine is required to process the obtained data mechanically. Inaddition, an accurate analysis has not yet been realized.

The above analysis of the data is made almost manually and it requiresgreat time and expenses.

In view of the disadvantages of the conventional systems, it is anobject of the present invention to provide an automotive drivinginstruction system which monitors the driving conditions more generallythan in conventional systems and also contributes to safer and moreeconomical driving. The automobile driving system according to thisinvention comprises a plurality of sensors mounted at various parts ofthe automobile in order to determine the driving conditions, calculatesthe driving conditions all the time on the basis of the states of therespective sensors, determines whether the result of calculation meets apredetermined conditions, and issues a warning on the basis of theresult of determination. The system according to this inventioncomprises also a replaceable external memory unit for storing theaccumulated value of not only all the alarms but also the accumulatedvalues of the respective alarms for each of causes of alarming, theexternal memory unit being adapted to be demounted at the end of adriving so that the data therein is processed on a processor. The datathus processed are indicated thereby to clarify and correct any habit ofthe driver involved.

According to a preferred embodiment of the present invention describedbelow, an alarm is issued while at the same time indicating the totalnumber of such an alarm, thus enhancing the consciousness of the driver.

Further, working switches for "driving", "loading", "rest" and the likeare provided, and each time these switches are operated, the state ofthe switches and the time involved are stored in the external memoryunit. The data thus stored are processed in a processor. In this way, itis possible to prepare data on the driving control useful forinstructing the driver on safe driving.

According to the present invention, the changes in vehicle speed orengine rotational speed are recorded merely in time series but areprocessed at real time, so that an alarm is issued and indicated fromtime to time against an unsafe behaviour or an uneconomical driving. Inthis way, a standard is set for the driving which has so far been oftengoverned by dogmatism, thus enlightening the driver.

Furthermore, the driver's work is properly distributed by recording theworking conditions of the driver so as not to impose harsh work on thedriver.

As a result, the system according to the present invention is expectedto make great contributions to the safety, economy and labor control ofthe driver and driving.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the construction of a system accordingto the present invention.

FIGS. 2 to 5 are flowcharts showing a series of programs for explainingthe operation of the system according to the present invention.

FIGS. 6 to 8 are flowcharts showing an interruption program forexplaining the operation of the system according to the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will be described below withreference to the accompanying drawings.

A block diagram of the construction of the apparatus according to thepresent invention is shown in FIG. 1. Reference numeral 1 designates asystem according to this invention, and numeral 2 a vehicle speed sensorfor detecting the speed of the automobile using a generally-known reedswitch for generating four pulses for each revolution of the axle.Numeral 3 designates an engine rotational speed sensor for detecting thenumber of revolutions of the engine which sensor uses a generally-knownelectromagnetic pick-up for the diesel engine for generating a pulse forevery two revolutions of the crank shaft of the engine.

Numeral 4 designates a neutral switch adapted to be closed when thetransmission is neutral. Numeral 5 designates a full throttle switchadapted to be closed when the accelerator pedal is depressedsubstantially to the full.

Numeral 6 designates an interface circuit for the vehicle speed sensorfor shaping and applying the waveform from the sensor to the input portof the microcomputer 17. Numeral 7 designates an interface circuit forthe engine rotational speed sensor, which also shapes the waveform ofthe signal from the sensor to apply the shaped signal to themicrocomputer. Numerals 8 and 9 denote interface circuits for theswitches for removing the chattering of the switches and applying theresulting signal to the microcomputer. For the interface circuits 6-9,use may be made of the wave form shaping circuit disclosed in DensoTechnical Report No. 225, page 27, published in February 1977, or DensoTechnical Report No. 240, page 80, published in May 1978.

Numeral 10 designates a timepiece circuit using an LSI for the watchesor clocks which LSI are commercially available, which directly applies atime output to the input port of the microcomputer. Numeral 11designates a time setting switch which may be operated to set the time.

The time piece circuit 10 is directly supplied with the power from +Band -B terminals of the battery of the automobile, and the timeindicated thereon remains unchanged even by the cut-off of the keyswitch after being set.

Numeral 12 designates an indication section using four light-emittingdiodes of seven segments for numeral indication of four digits inaccordance with the output of the microcomputer. The indication sectionor indication device comprises a numerical display and alarm. Thenumerical display may be of the fluorescent display tube etc. typedisclosed by Ryoichi Mori, "Microcomputer Series 8, One ChipMicrocomputer", pp. 164-165, and pp. 136-137, published in 1979. As thealarm, a buzzer may be used.

Numeral 13 designates a working condition switch system comprised offour switches named "driving", "loading", "waiting" and "rest" inaccordance with the working condition of the driver. The four switchesare operatively interlocked with each other so that any one of theswitches may be selectively closed by the operation of the driver. Theworking condition switch 13 is constructed such that when the driveroperates to close any one of the four switches, all of other threeswitches open. This construction is such that the four switches areinterlocked as stated above. This construction itself is known inswitches of tape recorders, etc. For example, in a tape recorder, whenthe reverse switch is operated while the forward switch is in its closedstate, the forward switch is released automatically.

Numeral 14 designates an interface circuit for the external memory unit,which interface circuit is connected with the address line, the dataline and the control line of the microcomputer for switching thebidirectional bus lines. This interface circuit is of the same type asthe one used for the computers in general.

Numeral 15 designates a connector for connection with the externalmemory unit 16. The external memory unit 16 takes the form of memorycard including a semiconductor RAM board, a simple power supply like amercury cell and a connector. Numeral 18 designates a power circuit forgenerating a voltage of 5 V used for the internal parts of the presentsystem from the voltages at the +B and -B terminals of the automotivebattery and supplying the same to each block. The connections from thepower circuit 18 to the blocks are not shown in the drawings.

Numeral 19 designates a main switch for supplying or switching off powerfrom the power supply to the system in general. This main switch isinterlocked with the ignition switch and is adapted to open or cut offthe power only when the ignition switch is off.

A flowchart for explaining the general operation of the system is shownin FIG. 2. The operation of the embodiment of the present invention willbe explained in detail below.

In this system, the vehicle speed and the engine rotational speed arefetched by interruption process. First, the fetching of the vehiclespeed will be explained. The pulse generated in the vehicle sensor 2 iswaveform-shaped at the interface circuit 6, and applied to theinterruption terminal of the microcomputer 17. The microcomputer 17enters the vehicle speed interruption routine each time the rising edgearrives of the pulse is applied to this terminal. During the vehiclespeed interruption, the number of the interruptions is counted, and whenthe count reaches four, the data in the vehicle speed counter are storedin a memory (RAM) of the microcomputer 17. The vehicle speed counter isincremented in the timer interruption routine without being reset, andthis results that the time corresponding to the four vehicle speedpulses is measured and stored. Thus, while the pulses from the vehiclespeed sensor are applied, the period for the four pulses is alwaysmeasured and stored. The conversion from the time into vehicle speed iseffected by the main routine.

The engine rotational speed is also measured by the same method as thevehicle speed. In the case of the engine rotational speed, however, thefigure on the counter is stored each time the interruption occurs, andthe measuring counter is subsequentially cleared so that the timerequired for two revolutions of the engine is always measured. Theconversion from the particular time to rotational speed is effected bythe main routine.

The timer interruption will be now explained. This computer contains atimer for setting the timer value by program. According to theembodiment under consideration, the timer value is set to 1 msec so thatthe timer interruption routine is entered once every 1 msec.

In the timer interruption routine, the vehicle speed and enginerotational speed counters are incremented on the one hand and thecounters called CNT_(V), CNT_(G), CNT_(S) and CNT_(R) are incremented atthe same time. Each of these counters actually takes the form of RAM inthe microcomputer and is labelled as described above.

The counter CNT_(V) is for counting the time in which the vehicle speedexceeds a predetermined value of speed, the counter CNT_(G) for countingthe time in which the acceleration exceeds a predetermined value, thecounter CNT_(S) for counting the time in which the number of revolutionsof the engine exceeds a predetermined value for the first, second orthird speed position of the transmission, and the counter CNT_(R) formeasuring the time in which the number of revolutions of the engineexceeds a predetermined value for the fourth or fifth speed of thetransmission.

The operation of the system will be explained with reference to the mainflowchart. The operation of the system according to the invention isstarted by switching on a power to the system.

After switching on of the power, the driver is required to check to seewhether the external memory unit is mounted first of all. In such achecking, according to this system, predetermined data are written at apredetermined place of the external memory unit followed immediately byreading them out and comparing them with the written data. By doing so,both the mounting and the replacement of the external memory unit arechecked at the same time.

When the external memory unit is mounted, data are read further from apredetermined address where the code of the driver is stored. Byconfirming the driver code, it is checked whether the driver is changedor not. If the driver is changed, the accumulated values and the countervalues stored in the computer thus far which belong to the precedingdriver are replaced with the accumulated values and counter values readfrom the recording address of a new memory unit and restored into thecomputer, thus making preparations for monitoring and recording thebehaviour of the new driver.

The accumulated values stored in the computer are subsequently producedand indicated on the indication section, so that the conditions of thenew driver are indicated.

Then the routine of vehicle speed calculation is entered. As describedabove, in the vehicle speed interrution routine, the period of fourvehicle speed pulses is always measured. Let such a period be Tv. Thenthe period Tv may be converted into the vehicle speed easily bycalculating

    V=Kv/Tv

where Kv is a constant.

The value V obtained by this calculation is stored not only in memoryunit of the computer but also in another memory unit with the precedingvalue V as V_(OLD). This is for calculating the acceleration.

After conversion into the vehicle speed, the resulting value isverified. Assuming that the value V₁ is a constant set by the program anoperation to carry out a comparison of V≧V₁ is made. That is, it isdetermined whether V is equal to or larger than V₁ . In other words, itis verified whether or not the present vehicle speed is higher than apredetermined value. According to the embodiment under consideration,for instance, V is set to be 80 km/h. If the vehicle speed is less than80 km/h, the counter CNT_(V) is always cleared, while if the vehiclespeed is higher than ₈₀ km/h, the counter CNT_(V) continues to beincremented in the timer interruption routine. It is determined whetheror not the data in counter CNT_(V) has exceeded the predetermined timein the later part of the main routine. If the data in the counterCNT_(V) has exceeded the predetermined time, the accumulated value isincremented while at the same time incrementing the counter value foroverspeed, and after storing the accumulated value and the counter valuein the external memory unit, the counter CNT_(V) is cleared.

By the above-mentioned operation, the time for which the speed of 80km/h is exceeded is determined, and when the speed exceeds 80 km/h forlonger than a predetermined length of time, an alarm is issued while atthe same time indicating and storing in the external memory unit theresult of the detection and alarming.

The acceleration is also checked in the same manner. For checking theacceleration, however, another memory unit is used tb store the latestvehicle speed V as V_(OLD) at regular intervals of time. For measuring apredetermined length of time, on the other hand, an acceleration counteris used. When the timing of checking the acceleration arrives, thisacceleration counter is cleared for checking the acceleration. Theacceleration is checked in such a manner that the value V_(OLD) whichwas stored a predetermined time before is subtracted from the latestvehicle speed V obtained by the speed calculation as shown below.

    V-V.sub.OLD

By effecting this calculation, a speed variation for a predeterminedlength of time is recognized.

The value of acceleration G thus calculated is checked, and if it issmaller than the acceleration G₁ set in the program, the counter CNT_(G)is cleared, while if the acceleration G is larger than the value G₁, thecounter CNT_(G) is left uncleared, with the result that the time forwhich the predetermined level of acceleration is exceeded is determinedas the count on the counter CNT_(G).

As in the case of vehicle speed, the value on the counter CNT_(G) ischecked in the main routine, and when the excess continues for longerthan a predetermined length of time, the accumulated value isincremented while at the same time incrementing the count on theacceleration counter. The resulting value is stored in the externalmemory unit and an alarm is issued on the one hand and the counterCNT_(G) is cleared on the other hand. According to the embodiment underconsideration, the time of 2 seconds is set for the counter CNT_(G), and0.07 G is set as the value of G₁, so that when the acceleration of morethan 0.07 G continues for longer than 2 seconds, an alarm is issued andthe fact is stored in the external memory unit.

In monitoring the engine rotational speed which depends on thetransmission position, two setting are provided for the first, secondand third speeds, and the fourth and fifth speeds.

Specifically, since the low gear position is used for vehicle start andrequires a high rotational speed unavoidably, a single setting fails tomeet the actual operating conditions. Also, the program is made suchthat it is not regarded as a bad driving only when the vehicle runs atthe third speed with full throttle at low acceleration in view of thecase in which the vehicle runs on a long ascendant slope with full load.

In other words, in the step 1 and subsequent steps in the flowchart, theengine rotational speed is calculated first of all. This calculation ismade in the same manner as the vehicle speed by the following equation:

    R=K.sub.R /T.sub.R

where T_(R) is the value on the engine speed counter sampled during theengine speed interruption, and K_(R) is a constant.

The value R obtained by this calculation is stored in the memory. Afterconverting the result of calculation into the rotational speed, it ischecked whether R is equal to or larger than R₁ (R₁ =3000 rpm). If thevalue R is lower than 3000 rpm, the counter CNT_(S) is cleared. Then itis checked whether R is equal to or larger than R₂ (R₂ =2500 rpm), andwhen the value R is smaller than 2500 rpm, the counter CNT_(R) iscleared.

In this way, when the engine speed is 3000 rpm or higher, the countersCNT_(S) and CNT_(R) continue to be incremented by the timerinterruption, and when the engine speed is 2500 rpm or more and lessthan 3000 rpm, the counter CNT_(R) alone continues to be incremented bythe timer interruption, thus determining the time in which the two setvalues are exceeded.

After these operations, the neutral switch is checked and if it ispositioned at neutral, the counters CNT_(S) and CNT_(R) are clearedfollowed by a jump to the symbol 3 in the flowchart. This is because inthe case of neutral position, the shift position is inaccurate and therotational speed is not checked accurately.

In the case where the neutral switch is not at neutral position, on theother hand, it is checked which of the above-mentioned two settingsshould be compared. In the case of transmission position of the fourthor fifth speed, it is checked whether the value on counter CNT_(R) isequal to or larger than T_(R) (CNT_(R) ≧T_(R)). If the value on thecounter CNT_(R) is equal to or more than T_(R), namely, if the time forwhich the engine rotational speed exceeds 2500 rpm at the fourth orfifth speed continues for T_(R) or more, the driving involved isconsidered to be bad, and the accumulated value is incremented on theone hand and the counter for the engine rotational speed is incrementedon the other hand. Further, the result is stored in the external memoryunit while at the same time issuing an alarm and clearing the counterCNT_(R).

When the value of the counter CNT_(R) is less than T_(R), no action istaken but the process is jumped to symbol 3 in the flowchart to continuethe incrementation of the counter CNT_(R).

At the transmission position of the first, second or third speed, it ischecked whether the value on counter CNT_(S) is equal to or more thanT_(S). When the value on the counter CNT_(S) is equal to or more thanT_(S), namely, when the time for which the engine rotational speedexceeds 3000 rpm at the first, second or third speed continues for T_(S)or more, the driving involved is considered inferior, with the resultthat the accumulated value is incremented on the one hand and the valueon the engine rotational speed counter is stored in the external memoryunit on the other hand. Further, an alarm is issued and the counterCNT_(S) is cleared. In the case of checking the counter CNT_(S),however, as mentioned above, such an exception is made that when theacceleration is G₂ (0.02 G) or lower at the third speed with thethrottle fully open, the driving involved is not considered inferior andthe counter CNT_(S) is cleared.

By the operations described above, it is monitored always whether thevehicle speed, acceleration and engine rotational speed are within arange of appropriate values, and if any of the vehicle speed etc.exceeds the appropriate value, an alarm is issued to warn the driverwhile at the same time indicating the accumulated value. Also, thecounts on the respective counters are stored in the external memoryunit, so that such data may be processed in a processor not shown.

After these operations, the states of the working condition switch arechecked. If it is determined that the state of the working conditionswitch has changed, it is checked to see whether the external memoryunit is mounted or not. If the external memory unit is mounted, theaddress data to store the working condition is read from the externalmemory unit, and the present switch condition and the present time dataare stored in that address. After this operation, the address for thenext storage is calculated, and the result of the calculation is storedin a predetermined place in the external memory unit.

The general operation of the system according to the present inventionis now completed, and the process is returned to the top of theflowchart, and the above-mentioned monitoring operation is continueduntil power is cut off.

The external memory unit employed in this embodiment comprises a CMOSmemory circuit, a back-up battery for holding the data in the memorycircuit, a case containing the memory circuit, and a connector attachedthereto. The external memory unit is constructed such that reading orwriting of the memory may be made freely by connecting the memorythrough the connector to the bus lines of the microcomputer.

The construction of the system according to the present embodiment issummarized in A to F below.

A. A driving instruction system which calculates the driving conditionsof the automobile on the basis of the states of the sensors provided atvarious parts of the automobile, and issues an alarm when the result ofcalculation becomes equal to any of a plurality of predeterminedconditions.

B. System of A which accumulates the number of alarms each time ofissuance of an alarm and indicates the number.

C. A system of A which comprises therein a plurality of counterscorresponding to the plurality of conditions, and increments and storesthe data in the counter involved each time of issuance of an alarm.

D. A system of A which comprises a replaceable external memory unit forstoring the accumulated value of B and the data in the counters of Ceach time of issuance of an alarm.

E. A system according to D which comprises a plurality of switchescorresponding to the working conditions of the driver, and a clock, andstores the condition of the switch operated and the time of switchoperation in time sequence in the external memory unit in response tothe operation of the switch.

F. A system according to D, which stores the code of the driver at apredetermined address of the external memory unit beforehand and detectsthe replacement of the external memory by reading the code at everypredetermined period, reads accumulated values of issuance of alarm andthe values of the counters recorded in the external memory unit andrewrites the read out data, and carries out indication of theaccumulated value and storing of the same in the external memory unit onthe basis of the values obtained after the rewriting from the nextissuance of the alarm.

In the above-described embodiment, instead of monitoring the enginerotational speed associated with the vehicle speed, acceleration andtransmission position and issuing an alarm and storing the result ofmonitoring in the external memory unit, the total number of enginerotations may be counted and indicated or stored in the external memoryunit with equal effect.

Also, the distance coverage may be calculated or recorded from thevehicle speed, or a plurality of settings of the vehicle speed, enginerotational speed and the acceleration may be indicated or recorded inhistogram.

Furthermore, not only the running conditions or the working conditionsbut also a combination of other switching data may be recorded. Forinstance, in combination with the fuel flow meter, the data on fuelefficiency and fuel consumption in relation to the running conditionsmay be recorded, thus contributing to an economical driving.

We claim:
 1. An automotive driving instruction system comprising:aplurality of sensors disposed at various parts of the automobile fordetecting the driving conditions of the automobile; a computer forreading the outputs of said sensors, calculating a plurality of valuesrepresenting the driving conditions of the automobile, and controllingissuance of an alarm when any of the results of the calculations of saidvalues becomes equal to the corresponding one of predetermined settingsassociated with the values; a replaceable external memory unit forstoring the accumulated values of said alarm, and the accumulated valuesof said alarm for respective causes by the processing operation of saidcomputer, said external memory being adapted to indicate the stored databy the processing operation of a data processing unit.
 2. A systemaccording to claim 1, further comprising an indication device, saidcomputer applying a signal representing the accumulated value of analarm to said indication device when controlling issuance of said alarm,said indication device accordingly indicating the number of generationsof alarms.
 3. A system according to claim 1, wherein said computercontains an internal memory operative as a plurality of counterscorresponding to said plurality of values representing the drivingconditions, and means for incrementing the data of a correspondingcounter and storing the same each time the calculation of said pluralityof values reaches the predetermined settings and the generation of alarmis controlled.
 4. A system according to claim 1, further comprising aplurality of switches corresponding to the working conditions of thedriver respectively, a clock, and means for storing the states of saidswitches and the time of operation thereof in said external memory unitin accordance with the operation of said switches.
 5. A system accordingto claim 2, further comprising means for storing the code of the driverat a predetermined address of said external memory unit, said computerreading out the data stored at said address at regular intervals of timefor detecting any replacement of said external memory unit, saidcomputer reading out the accumulated value of generations of the alarmsand the accumulated value of the alarms and rewriting the same thereinin response to the detection of the replacement of said external memoryunit, means for accumulating the subsequent alarms on the basis of thevalues after the rewriting, for storing the accumulated value in saidexternal memory unit, and means for applying said accumulated value tosaid indication device and indicating the same thereon at the time of anissuance of an alarm.
 6. An automotive driving instruction systemcomprising:a plurality of sensors disposed at various parts of theautomobile for detecting the driving conditions of the automobileincluding running speed of the automobile and rotational speed of theautomobile engine; a computer for reading the outputs of said sensors,calculating a plurality of values representing respective duration of atleast one of (a) excess running speed of the automobile, (b) excessacceleration of the automobile and (c) excess rotational speed of theautomobile engine, and controlling issuance of an alarm when any one ofthe results of the calculations of said values reaches the correspondingone of predetermined settings associated with the values; and areplaceable external memory unit for storing the accumulated values ofsaid alarm, and the accumulated values of said alarm for respectivecauses by the processing operation of said computer.
 7. A systemaccording to claim 6, further comprising an indication device, saidcomputer applying a signal representing the accumulated value of analarm to said indication device when controlling issuance of said alarm,said indication device accordingly indicating the number of generationsof alarms.
 8. A system according to claim 6, wherein said computercontains an internal memory operative as a plurality of counterscorresponding to said plurality of values for measuring said respectivedurations, and means for incrementing the data of a correspondingcounter and storing the same each time the calculation of said pluralityof values reaches the predetermined settings and the generation of alarmis controlled.
 9. A system according to claim 6, further comprising aplurality of switches corresponding to the working conditions of thedriver respectively, a clock, and means for storing the states of saidswitches and the time of operation thereof in said external memory unitin accordance with the operation of said switches.
 10. A systemaccording to claim 9, further comprising means for storing the code ofthe driver at a predetermined address of said external memory unit, saidcomputer reading out the data stored at said address at regularintervals of time for detecting any replacement of said external memoryunit, said computer reading out the accumulated value of generations ofthe alarms and the accumulated value of the alarms and rewriting thesame therein in response to the detection of the replacement of saidexternal memory unit, means for accumulating the subsequent alarms onthe basis of the values after the rewriting, for storing the accumulatedvalue in said external memory unit, and means for applying saidaccumulated value to said indication device and indicating the samethereon at the time of an issuance of an alarm.